Water purifier and control method for water purifier

ABSTRACT

Provided is a water purifier comprising: a filter unit filtering water supplied from a water source, including a reverse osmosis filter; a discharge unit discharging water filtered by the filter unit externally; a flushing portion connected to the reverse osmosis filter; and a controller configured to flow water filtered by the reverse osmosis filter to the flushing portion, and to flush the reverse osmosis filter.

PRIORITY

This application is a Divisional Application of U.S. patent applicationSer. No. 16/084,116 filed with U.S. Patent and Trademark Office on Sep.11, 2018, which is a National Phase Entry of International ApplicationNo. PCT/KR2017/002437, which was filed on Mar. 7, 2017, and claimspriority to Korean Patent Application Nos. 10-2016-0029359 and10-2016-0128241, which were filed on Mar. 11, 2016 and Oct. 5, 2016,respectively, the content of each of which is incorporated herein byreference.

BACKGROUND 1. Field

The present disclosure relates to a water purifier.

2. Related Art

A water purifier may be a device that treats water and supplies thetreated water to a user. In a water purifier, water may be treated, suchas by being filtered or electrolyzed, to make alkaline water, or thelike, or carbon dioxide may be dissolved in water to make carbonatedwater, and the treated water may then be supplied to a user.

In a case that water is filtered and supplied to a user, a waterpurifier may include a water filter for filtering water.

For example, a water purifier may include a reverse osmosis filterhaving a reverse osmosis membrane as a filter for purifying water. Thereverse osmosis filter may be divided into a non-filtration side portionand a filtration side portion by the reverse osmosis membrane. Whenwater is introduced into the non-filtration side portion of the reverseosmosis filter, water passing through the reverse osmosis membrane maybe filtered, and water not passing through the reverse osmosis membranemay be drained as domestic water.

Meanwhile, in a case that the water is not filtered through the reverseosmosis filter, the water in the filtration side portion of the reverseosmosis filter may move to the non-filtration side portion due toosmotic pressure. Therefore, total dissolved solids (TDS) concentrationsof the water in the filtration side portion and the non-filtration sideportion of the reverse osmosis filter may be similar to each other.

In such a state, when the filtration of water through the reverseosmosis filter is started again, water having a relatively high TDSconcentration in the filtration side portion of the reverse osmosisfilter may initially be supplied to a user, known as a creep phenomenon.

In recent years, studies have been actively conducted into techniquesfor performing automatic flushing after extracting purified water toimprove the lifespan and the creep phenomenon of the reverse osmosisfilter. However, in a case of a water purifier performing automaticflushing, there is a problem in that a recovery rate may be lowereddepending on extraction amounts of purified water.

There is a need for a water purifier performing automatic flushing inorder to improve the creep phenomenon more efficiently in a waterpurifier using a reverse osmosis filter. Further, there is a need for asolution for solving the problem that the recovery rate decreasesdepending on cases, in the water purifier performing the automaticflushing.

SUMMARY

According to an aspect of the present disclosure, A water purifiercomprising: a filter unit filtering water supplied from a water sourceand including a reverse osmosis filter divided into a non-filtrationside portion and a filtration side portion by a reverse osmosismembrane; a discharge unit discharging water filtered by the filter unitexternally; a flushing portion connected between the non-filtration sideportion and the filtration side portion; and a controller configured toflow water filtered by the reverse osmosis filter to the non-filtrationside portion through the flushing portion so as to flush the reverseosmosis filter.

According to an aspect of the present disclosure, the creep phenomenonmay be more efficiently improved by flushing the reverse osmosis filterwith water filtered by the reverse osmosis filter. In addition, it ispossible to solve the problem that the recovery rate is lowered, when anextraction amount of the purified water is relatively low, by shuttingoff the discharge of domestic water, or by releasing the shut-off,depending on a flow rate of extraction of the purified water.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view illustrating a water purifier according to a firstembodiment of the present disclosure;

FIG. 2 is a view illustrating a control operation of a controller, whenan amount of extracted purified water exceeds a predetermined amount;

FIG. 3 is a view illustrating a control operation of a controller, whenan amount of extracted purified water is lower than a predeterminedamount;

FIG. 4 is a view illustrating an operation of storing purified water ina flushing tank;

FIG. 5 is a view illustrating a flushing operation;

FIG. 6 is a graph illustrating a recovery rate of a water purifieraccording to an embodiment of the present disclosure;

FIG. 7 is a view illustrating a control method of a water purifieraccording to an embodiment of the present disclosure;

FIG. 8 is a view illustrating an embodiment of an operation of flushinga filter unit of FIG. 7 ;

FIG. 9 is a schematic view illustrating a water purifier according to asecond embodiment of the present disclosure;

FIGS. 10 to 12 are views illustrating operations of a water purifieraccording to a second embodiment of the present disclosure;

FIG. 13 is a schematic view illustrating a water purifier according to athird embodiment of the present disclosure;

FIGS. 14 to 16 are views illustrating operations of a water purifieraccording to a third embodiment of the present disclosure;

FIG. 17 is a schematic view illustrating a water purifier according to afourth embodiment of the present disclosure; and

FIGS. 18 to 20 are views illustrating operations of a water purifieraccording to a fourth embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the present disclosure will bedescribed with reference to the accompanying drawings.

However, the embodiments of the present disclosure may be modified tohave various other forms, and the scope of the present disclosure is notlimited to the embodiments described below. Further, the embodiments ofthe present disclosure are provided to more fully explain the presentdisclosure to those skilled in the art.

In the drawings referred to in the present disclosure, elements havingsubstantially the same constructions and functions will be denoted bythe same reference numerals, and the shapes and sizes of the elementsand the like in the drawings may be exaggerated for clarity.

FIG. 1 is a view illustrating a water purifier according to a firstembodiment of the present disclosure.

Referring to FIG. 1 , a water purifier 100 according to a firstembodiment of the present disclosure may include a filter unit 110, aflow rate sensor 120, a flushing portion 130, and a controller 140. Inaddition, the water purifier 100 may also include a raw water flow path1 for introducing raw water, a purified water flow path 2 fordischarging purified water, a domestic water flow path 3 for dischargingdomestic water, a flushing flow path 4 for discharging flushed water,and a flushing purified water supplying flow path 5 for supplyingpurified water to be flushed to the filter unit 110. Valves 10, 30, 40,and 50, or a check valve 135, may be provided to control flow of water.A water inflow pump 21 may be additionally provided at one point on theraw water flow path 1, for example, between a water inflow valve 50 anda second flow path switching valve 133 to smoothly introduce raw waterinto the filter unit 110, as needed.

The filter unit 110 may filter raw water flowing from the raw water flowpath 1 to generate purified water. In this case, the filter unit 110 mayinclude a raw water inlet 111 connected to the raw water flow path 1, apurified water outlet 112 connected to the purified water flow path 2for discharging purified water, and a domestic water outlet 113connected to the domestic water flow path 3 for discharging the domesticwater generated during the generation of purified water. The filter unit110 may be a reverse osmosis filter.

The flow rate sensor 120 may be disposed in the purified water flow path2, and may sense a flow rate of purified water discharged from thepurified water outlet 112 of the filter unit 110. The flow rate sensor120 may sense a flow rate of purified water discharged through thepurified water flow path 2 per unit time, and may output a value of thesensed flow rate to the controller 140.

The flushing portion 130 may be a portion for cleaning the filter unit110, may store purified water discharged through the purified wateroutlet 112, and may supply the stored purified water to the filter unit110 through the raw water inlet 111.

In one embodiment, the flushing portion 130 may include a flushing tank131, a first flow path switching valve 132, a second flow path switchingvalve 133, and a third flow path switching valve 134, which areconfigured to store purified water discharged from the purified wateroutlet 112 of the filter unit 110, and to supply the purified water tothe raw water inlet 111 of the filter unit 110. The flushing portion 130may further include a first check valve 135, installed on the flushingpurified water supplying flow path 5 connecting between the second flowpath switching valve 133 and the third flow path switching valve 134 toprevent a reverse flow of the raw water.

The flushing pump 22 may be further provided, as needed, at one point onthe flushing purified water supplying flow path 5 to supply smoothlypurified water during the flushing operation.

The flushing portion 130 may further include a fourth flow pathswitching valve 136, a flushing flow path 4, and a flushing valve 40,which are configured to discharge the flushed water of the filter unit110 externally. In addition, a first domestic water valve 20 forpreventing a reverse flow of domestic water, and a second domestic watervalve 30 for shutting off domestic water may be arranged in the domesticwater flow path 3.

The flushing portion 130 may be operated under control of the controller140. A specific operation of the flushing portion 130 will be describedin detail with reference to FIGS. 4 to 5 .

The controller 140 may control the overall operation of the waterpurifier.

When a purified water extracting input is provided, the controller 140may generate purified water by introducing raw water into the filterunit 110, and may extract the purified water through an extract port.

The controller 140 may flush the filter unit 110 to improve the lifetimeof the filter unit 110 and a reverse osmosis (RO) creep phenomenon, whenthe extraction of purified water is completed.

In this case, even in a case that an amount of water extracted at thetime of extraction of one time is very low, when the flushing proceeds,there may be problems that a recovery rate is lowered, and an amount ofwater to be discarded is increased.

In order to solve such problems, the controller 140 may shut-off thedischarge of domestic water, when an amount of purified water extractedat the time of one-time water purification is lower than a predeterminedamount. In other words, the accumulated flow rate of the purified wateris an accumulated flow rate from the start of the extraction of purifiedwater to the completion of the extraction of purified water.

In this case, the predetermined amount may be an amount whose variationof a TDS value of purified water generated by the filter unit 110 may bewithin a predetermined range, even when the discharge of domestic wateris shut off. In one embodiment, the predetermined amount may bedetermined by a preliminary experiment. In addition, the predeterminedamount may be proportional to a capacity of the filter unit.

In one embodiment, the controller 140 may include at least one of aprocessing unit and a memory. The processing unit may include a centralprocessing unit CPU, a graphics processing unit GPU, a microprocessor,an application specific integrated circuit ASIC, a field programmablegate array FPGA, or the like, and may have a plurality of cores. Thememory may be a volatile memory, a non-volatile memory, or a combinationthereof.

FIG. 2 is a view illustrating a control operation of a controller, whenan amount of extracted purified water exceeds a predetermined amount.

Referring to FIG. 2 , the controller 140 may control the fourth flowpath switching valve 136 and the second domestic water valve 30 todischarge domestic water generated by the filter unit 110 externallythrough the domestic water flow path 3, when an accumulated flow rate atthe time of one-time water purification calculated based on the flowrate of the purified water per unit time measured by the flow ratesensor 120 is equal to or greater than a value of a predetermined amount(for example, 0.5 liter).

FIG. 3 is a view illustrating a control operation of a controller, whenan amount of extracted purified water is lower than a predeterminedamount.

Referring to FIG. 3 , the controller 140 may control the fourth flowpath switching valve 136 and the second domestic water valve 30 toshut-off the discharge of the domestic water, when an accumulated flowrate at the time of one-time water purification calculated based on theflow rate of the purified water per unit time measured by the flow ratesensor 120 is less than a value of a predetermined amount (for example,0.5 liter).

In one embodiment, in the second domestic water valve 30, a state inwhich a valve of the second domestic water valve 30 is closed may be setas a default.

For example, the second domestic water valve 30 may maintain theshut-off state. Depending on an input state of a purified waterextracting input, purified water may be generated and extracted. When anaccumulated flow rate of the extracted purified water is equal to orlarger than a predetermined amount, the controller 140 may control thesecond domestic water valve 30 to discharge domestic water externally.

FIG. 4 is a view illustrating an operation of storing purified water ina flushing tank.

FIG. 4 , when an extraction of purified water is completed, thecontroller 140 may control the first flow path switching valve 132 suchthat purified water discharged through the purified water outlet 112 ofthe filter unit 110 is stored in the flushing tank 131.

FIG. 5 is a view illustrating a flushing operation.

Referring to FIG. 5 , the controller 140 may control the water inflowvalve 50 to shut-off raw water inflowing into the filter unit 110, andmay control the second flow path switching valve 133 and the third flowpath switching valve 134 to provide purified water stored in theflushing tank 131 to the raw water inlet 111 of the filter unit 110,when purified water of an amount equal to or larger than a predeterminedamount is stored in the flushing tank 131.

The controller 140 may control the fourth flow path switching valve 136and the flushing valve 40 to discharge purified water inflowing into thefilter unit 110 externally through the flushing flow path 4.

FIG. 6 is a graph illustrating a recovery rate of a water purifieraccording to an embodiment of the present disclosure.

Referring to FIG. 6 , it is confirmed that the present disclosure (a) inwhich domestic water is shut-off depending on an accumulated flow rateat the time of one-time extraction of purified water may be improved interms of the recovery rate than the conventional case (b) in whichdomestic water is not shut-off regardless of an accumulated flow rate,in a low extraction amount section.

Hereinafter, a control method of a water purifier according to anembodiment of the present disclosure will be described with reference toFIGS. 7 to 8 .

The following control method of the water purifier may be performed inthe water purifier according to the first embodiment described abovewith reference to FIGS. 1 to 6 , and hence the same or equivalentcontents will not be described in duplicate.

However, a water purifier to which a control method of a water purifierto be described later is applied is not limited to the first embodimentdescribed above, but may be applied to a water purifier according tosecond to fourth embodiments to be described later, for example.

FIG. 7 is a view illustrating a control method of a water purifieraccording to an embodiment of the present disclosure, and FIG. 8 is aview illustrating an embodiment of an operation of flushing a filterunit of FIG. 7 .

Referring to FIG. 7 , a controller 140 may generate purified water byintroducing raw water into a filter unit 110, depending on a purifiedwater extracting input (S100).

The generated purified water may be extracted through a purified waterflow path 2 (S200).

A flow rate sensor 120 may measure a flow rate of purified waterextracted through the purified water flow path 2 per unit time (S300).

When an accumulated flow rate at the time of one-time extraction ofpurified water calculated on the basis of a flow rate of the purifiedwater per unit time measured by the flow rate sensor 120 is lower than apredetermined amount (S400), the controller 140 may control a seconddomestic water valve 30 and a fourth flow path switching valve 136 toshut-off discharge of domestic water (S500). Meanwhile, when anaccumulated flow rate at the time of one-time extraction of purifiedwater calculated on the basis of a flow rate of the purified water perunit time measured by the flow rate sensor 120 is equal to or largerthan a predetermined amount (S400), the controller 140 may control asecond domestic water valve 30 and a fourth flow path switching valve136 to release the shut-off of the discharge of domestic water (S550).According to an embodiment, in a case that a state in which a seconddomestic water valve 30 is closed is set as a default, when thedischarge of the domestic water is shut-off (S500), a state of thesecond domestic water valve 30 may be maintained as it is, i.e., asclosed; while, when the shut-off of the discharge of the domestic wateris released (S550), the second domestic water valve 30 may be opened todischarge the domestic water.

The controller 140 may flush the filter unit 110 using purified watergenerated by the filter unit 110 (S600).

In one embodiment, the flushing operation (S600) may include anoperation of storing the purified water generated in the filter unit 110in the flushing tank 131 (S610), and an operation of supplying thepurified water stored in the flushing tank to a raw water inlet 111 ofthe filter unit 110 (S620).

The controller 140 may control a fourth flow path switching valve 136 todrain flushed water externally (S700).

Hereinafter, a water purifier according to a second embodiment of thepresent disclosure will be described with reference to FIGS. 9 to 12 .

FIG. 9 is a schematic view illustrating a water purifier according to asecond embodiment of the present disclosure, and FIGS. 10 to 12 areviews illustrating operations of a water purifier according to a secondembodiment of the present disclosure.

As illustrated in FIG. 9 , a water purifier 200 according to a secondembodiment of the present disclosure may include filter units 210, 210′,and 210″, a flushing portion 230, a controller 240, and a discharge unit250.

The filter units 210, 210′, and 210″ may filter water supplied from awater source. To this end, the filter unit 210 may be a reverse osmosisfilter 210, and may include a pre-treatment filter 210′ and apost-treatment filter 210″ at front and rear ends of the reverse osmosisfilter 210, respectively.

The reverse osmosis filter 210 may be partitioned into a non-filtrationside portion 215 and a filtration side portion 216 by a reverse osmosismembrane 214, as illustrated in FIG. 9 . For example, the reverseosmosis filter 210 may be partitioned into the non-filtration sideportion 215 and the filtration side portion 216 by providing the reverseosmosis membrane 214 in a rolled state within the reverse osmosis filter210.

The configuration in which the reverse osmosis filter 210 is partitionedinto the non-filtration side portion 215 and the filtration side portion216 by the reverse osmosis membrane 214 is not particularly limited, butany well-known configurations are possible.

A raw water flow path 1 and a domestic water flow path 3 may beconnected to the non-filtration side portion 215 of the reverse osmosisfilter 210.

Water may be introduced into the reverse osmosis filter 210, i.e., thenon-filtration side portion 215 of the reverse osmosis filter 210through the raw water flow path 1, as illustrated in FIGS. 10 to 12 .

In addition, as illustrated in FIGS. 10 and 11 , domestic water whichhas not passed through a reverse osmosis membrane 214 of a reverseosmosis filter 210 and has not filtered, may be drained externallythrough a domestic water flow path 3.

Meanwhile, as illustrated in FIG. 12 , flushed water that has beenflushed with a reverse osmosis filter 210, i.e., a non-filtration sideportion 215 of the reverse osmosis filter 210, may be drained externallythrough a domestic water flow path 3.

The raw water flow path 1 may be provided with a water inflow valve 50.The water inflow valve 50 may be electrically connected to thecontroller 240. When the water inflow valve 50 is opened by thecontroller 240, water may be introduced into the reverse osmosis filter210 through the raw water flow path 1, as illustrated in FIGS. 10 and 11. The water inflow valve 50 may be installed at a rear end of thepre-treatment filter 210′, as illustrated in FIGS. 9 to 12 . However,the position of the water inflow valve 50 is not limited thereto. Forexample, the water inflow valve 50 may be installed at a front end ofthe pre-treatment filter 210′.

A domestic water valve 30 may be provided on the domestic water flowpath 3. As illustrated in FIGS. 10 and 11 , domestic water that has notbeen filtered by the reverse osmosis filter 210 may be drainedexternally by the domestic water valve 30, or, as illustrated in FIG. 12, flushed water that has flushed the reverse osmosis filter 210 may bedrained externally. Although FIGS. 9 to 12 illustrate that both thedomestic water and the flushed water are discharged through one domesticwater flow path 3, the domestic water flow path and the flushing flowpath may be separately provided such that the domestic water and theflushed water are discharged through separate flow paths. In this case,valves may be installed in each of the flow paths, respectively.

The purified water flow path 2 may be connected to the filtration sideportion 216 of the reverse osmosis filter 210. The filtered water may bedischarged through the reverse osmosis membrane 214 of the reverseosmosis filter 210 through the purified water flow path 2, asillustrated in FIGS. 10 and 11 .

As described above, in order to filter water supplied from the watersource, the filter units 210, 210′, and 210″ may further include apre-treatment filter 210′ and a post-treatment filter 210″, asillustrated in FIG. 9 , in addition to the reverse osmosis filter 210described above.

In the filter units 210, 210′, and 210″, the purified water filterfurther included in addition to the reverse osmosis filter 210 forfiltering water supplied from the water source is not particularlylimited, and any well-known water filters may be included.

The pre-treatment filter 210′ may be connected to a water source (notillustrated), for example, a source of raw water, such as tap water, bya water inflow line, as illustrated in FIG. 9 . In addition, thepre-treatment filter 210′ may be connected to the reverse osmosis filter210 by the raw water flow path 1.

Therefore, when the water inflow valve 50 of the raw water flow path 1is opened by the controller 240, water of the water source, for example,raw water, may first be introduced into the pre-treatment filter 210′through the water inflow line, and may be filtered, as illustrated inFIGS. 10 and 11 .

The water filtered by the pre-treatment filter 210, i.e., the purifiedwater may be introduced into the reverse osmosis filter 210 through theraw water flow path 1.

The post-treatment filter 210″ may be connected to the reverse osmosisfilter 210 by the purified water flow path 2. The post-treatment filter210″ may also be connected to the discharge unit 250 by a water outflowline. The water outflow line may be provided with a water outflow valve10 electrically connected to the controller 240.

Therefore, when the water outflow valve 10 is opened by the controller240, the water filtered by the reverse osmosis filter 210, i.e., thepurified water may be introduced into the post-treatment filter 210″through the purified water flow path 2, and may be filtered, asillustrated in FIG. 10 .

The water filtered by the post-treatment filter 210″, i.e., the purifiedwater may flow through the water outflow line, may be dischargedexternally through the discharge unit 250, and may be supplied to auser.

The discharge unit 250 may discharge the water filtered by the filterunits 210, 210′, and 210″, i.e., the purified water externally, asillustrated in FIG. 10 .

The discharge unit 250 may be connected to the filter unit 210, 210′,and 210″, such as the post-treatment filter 210″ by the water outflowline, as illustrated in FIG. 9 .

When the water outflow valve 10 of the water outflow line may be openedby the controller 240, the water filtered in the filter units 210, 210′,and 210″, i.e., the purified water may be discharged externally throughthe discharge unit 250, and may be supplied to a user.

The discharge unit 250 may include, for example, a cock or a faucet (notillustrated), connected to a water outflow line, and discharges thewater filtered by the filter units 210, 210′, and 210″, i.e., thepurified water. However, the structure of the discharge unit 250 is notparticularly limited, and any known structure may be used as long as itis capable of discharging the water filtered by the filter unit 210,210′, and 210″ externally.

The flushing portion 230 may be connected to the reverse osmosis filter210. The flushing portion 230 may include a flushing purified watersupplying flow path 5, connected to the raw water flow path 1 connectedto the non-filtration side portion 215 of the reverse osmosis filter210, and the purified water flow path 2 connected to the filtration sideportion 216 of the reverse osmosis filter 210, respectively, asillustrated in FIG. 9 .

A first check valve 235 for allowing water to only flow in the directionof the raw water flow path 1 may be provided in the flushing purifiedwater supplying flow path 5. Therefore, as illustrated in FIGS. 10 and11 , when the water filtered by the pre-treatment filter 210′ flows intothe reverse osmosis filter 210 through the raw water flow path 1, thewater filtered by the pre-treatment filter 210′ may not flow into theflushing purified water supplying flow path 5 through the raw water flowpath 1.

As illustrated in FIGS. 11 and 12 , only when the reverse osmosis filter210 is flushed, the water filtered through the reverse osmosis filter210, i.e., the purified water may be introduced into and flow into theflushing purified water supplying flow path 5 through the purified waterflow path 2.

As described above, the water flowing into the flushing purified watersupplying flow path 5 may flow into the reverse osmosis filter 210through the raw water flow path 1 to flush the reverse osmosis filter210, and may be drained externally through the domestic water flow path3, as illustrated in FIG. 12 .

Meanwhile, a flushing valve (not illustrated), other than the firstcheck valve 235 described above, may be provided in the flushingpurified water supplying flow path 5. The flushing valve may beelectrically connected to the controller 240.

In such a configuration, when the water filtered by the pre-treatmentfilter 210′ is introduced into the reverse osmosis filter 210 throughthe raw water flow path 1, the flushing valve of the flushing purifiedwater supplying flow path 5 may be closed by the controller 240, asillustrated in FIGS. 10 and 11 .

Further, as illustrated in FIG. 12 , the flushing valve of the flushingpurified water supplying flow path 5 may be opened by the controller240, only when the reverse osmosis filter 210 is flushed.

The controller 240 may flow the water filtered by the reverse osmosisfilter 210 to the flushing portion 230, and flush the reverse osmosisfilter 210, i.e., the non-filtration side portion 215 of the reverseosmosis filter 210.

Thereby, the non-filtration side portion 215 of the reverse osmosisfilter 210 may also have water with a low TDS concentration, forexample, similar to a TDS concentration in the filtration side portion216.

Even when water is not filtered through the filter units 210, 210′, and210″ including the reverse osmosis filter 210, the water in thefiltration side portion 216 of the reverse osmosis filter 210 may notmove to the non-filtration side portion 215 by osmosis.

Thus, a TDS concentration of water present in the filtration sideportion 216 of the reverse osmosis filter 210 may not be increased.

Therefore, when the filtration of water in the filter units 210, 210′,and 210″ including the reverse osmosis filter 210 is restarted, waterhaving a low TDS concentration may be discharged, even at the beginningof filtration to supply the same to a user.

Accordingly, when water is filtered using the reverse osmosis filter210, water having a high TDS concentration may be discharged at theinitial stage of filtration, and may be not supplied to a user.

The controller 240 may be electrically connected to the above-describedwater inflow valve 50 for supplying water to the filter units 210, 210′,and 210″, and to the above-described water outflow valve 10 fordischarging the filtered water through the discharge unit 250,respectively.

The controller 240 may open and close the water inflow valve 50 and thewater outflow valve 10 with a predetermined time difference, such thatthe water filtered by the reverse osmosis filter 210 flows into theflushing portion 230, for example, into the flushing purified watersupplying flow path 5 of the flushing portion 230.

To this end, the controller 240 may close the water outflow valve 10,after discharging the water filtered through the filter units 210, 210′,and 210″, i.e., the purified water through the discharge unit 250, andclose the water inflow valve 50 after a predetermined first set time.

When the water inflow valve 50 and the water outflow valve 10 are openedby the controller 240, the water of the water source, for example, theraw water, may be introduced into the pre-treatment filter 210′ throughthe water inflow valve, and may be filtered, as illustrated in FIG. 10 .

The water filtered by the pre-treatment filter 210′, i.e., purifiedwater may be introduced into the reverse osmosis filter 210 through theraw water flow path 1.

Further, as illustrated in FIG. 10 , the water filtered by the reverseosmosis filter 210 may be introduced into the post-treatment filter 210″through the purified water flow path 2, and the water not filtered bythe reverse osmosis filter 210, i.e., the domestic water may be drainedexternally through the domestic water flow path 3.

In addition, the water introduced into the post-treatment filter 210″may be filtered by the post-treatment filter 210″, may flow through thewater outflow line, may be discharged externally through the dischargeunit 250, and may be supplied to a user.

After the water filtered by the filter units 210, 210′, and 210″, i.e.,the purified water, is discharged through the discharge unit 250 by apredetermined amount desired by a user, the controller 240 may firstlyclose the water outflow valve 10, as illustrated in FIG. 11 .

Thus, the water that is filtered by the reverse osmosis filter 210 andflows in the purified water flow path 2, i.e., the purified water, maybe not introduced into the post-treatment filter 210″, and may beintroduced into the flushing purified water supplying flow path 5 of theflushing portion 230.

After the water outflow valve 10 is closed and a predetermined first settime proceeds, the controller 240 may close the water inflow valve 50.

Thus, the water filtered by the reverse osmosis filter 210 introducinginto the flushing purified water supplying flow path 5 of the flushingportion 230, i.e., the purified water, may be introduced into thereverse osmosis filter 210, i.e., the non-filtration side portion 215 ofthe reverse osmosis filter 210 through the flushing purified watersupplying flow path 5 and the raw water flow path 1, as illustrated inFIG. 12 .

The first set time described above may be, for example, a time at whicha sufficient amount of filtered water capable of flushing the reverseosmosis filter 210 may be introduced into the flushing purified watersupplying flow path 5 of the flushing portion 230.

The first set time is not particularly limited, and may be any time aslong as it is necessary to flush the reverse osmosis filter 210.

As described above, the water introduced into the non-filtration sideportion 215 of the reverse osmosis filter 210 may flush thenon-filtration side portion 215 of the reverse osmosis filter 210, andthen, as illustrated in FIG. 12 , may be drained externally through thedomestic water flow path 3.

The flushing of such a reverse osmosis filter 210 may be performed bythe controller 240 for a predetermined second set time. For example, thecontroller 240 may close the water inflow valve 50, and may close thedomestic water valve 30 after a predetermined second set time.

The second set time is not particularly limited, and may be any time aslong as it is sufficient to flush the reverse osmosis filter 210.

Hereinafter, a water purifier according to a third embodiment of thepresent disclosure will be described with reference to FIGS. 13 to 16 .

FIG. 13 is a schematic view illustrating a water purifier according to athird embodiment of the present disclosure, and FIGS. 14 to 16 are viewsillustrating operations of a water purifier according to a thirdembodiment of the present disclosure.

There is a difference that the water purifier according to the thirdembodiment of the present disclosure may include the water purifier 200according to the second embodiment of the present disclosure describedwith reference to FIGS. 9 to 12 , and may further include a flushingtank 331 in a flushing portion 330.

Therefore, the configurational difference will be mainly describedbelow, and the remaining configurations may be replaced with thosedescribed with reference to FIGS. 9 to 12 above.

In a water purifier 300 according to the third embodiment of the presentdisclosure, a flushing portion 330 may further include a flushing tank331, as illustrated in FIG. 13 .

The flushing tank 331 may be connected to a flushing purified watersupplying flow path 5. In the flushing tank 331, water filtered by areverse osmosis filter 310, i.e., purified water, may be stored, asillustrated in FIG. 15 . The filtered water stored in the flushing tank331 may be discharged from the flushing tank 331 to flush the reverseosmosis filter 310, as illustrated in FIG. 16 .

In such a configuration, when the water inflow valve 50 and the wateroutflow valve 10 are opened by the controller 340, water of watersource, for example, raw water may be introduced into the pre-treatmentfilter 310′ through a water inflow line, and may be firstly filtered, asillustrated in FIG. 14 .

The water filtered by the pre-treatment filter 310′ may be introducedinto the reverse osmosis filter 310 through the raw water flow path 1.

Further, as illustrated in FIG. 14 , the water filtered by the reverseosmosis filter 310 may be introduced into the post-treatment filter 310″through the purified water flow path 2 and may be filtered. The waterthat is not filtered by the reverse osmosis filter 310, i.e., thedomestic water, may be drained externally through the domestic waterflow path 3.

The water filtered by the post-treatment filter 310″ may flow in thewater outflow line, may be discharged externally through the dischargeunit 350, and may be supplied to a user.

After the water filtered by the filter units 310, 310′, and 310″, i.e.,the purified water, is discharged through the discharge unit 350 in apredetermined amount desired by a user, the controller 340 may firstlyclose the water outflow valve 10, as illustrated in FIG. 15 .

Thus, the water that is filtered by the reverse osmosis filter 310 andflows in the purified water flow path 2, i.e., the purified water may benot introduced into the post-treatment filter 310″, and may beintroduced into the flushing purified water supplying flow path 5 of theflushing portion 330.

Further, the water filtered by the reverse osmosis filter 310introducing into the flushing purified water supplying flow path 5 mayflow in the flushing purified water supplying flow path 5, and may bestored in the flushing tank 331.

After the water outflow valve 10 is closed and a predetermined first settime proceeds, the controller 340 may close the water inflow valve 50.

Thus, the water filtered by the reverse osmosis filter 310 stored in theflushing tank 331 of the flushing portion 330 may be introduced into thereverse osmosis filter 310, i.e., the non-filtration side portion 315 ofthe reverse osmosis filter 310 through the flushing purified watersupplying flow path 5 and the raw water flow path 1, as illustrated inFIG. 16 .

In this case, the first set time described above may be, for example, atime at which a sufficient amount of filtered water capable of flushingthe reverse osmosis filter 310 may be introduced into and stored in theflushing tank 331 of the flushing portion 330.

The first set time is not particularly limited, and may be any time aslong as it is necessary to flush the reverse osmosis filter 310.

The water introduced into the non-filtration side portion 315 of thereverse osmosis filter 310 may flush the non-filtration side portion 315of the reverse osmosis filter 310, and may be then drained externallythrough the domestic water flow path 3, as illustrated in FIG. 16 .

Further, after the water inflow valve 50 is closed, and a predeterminedsecond set time proceeds, for example, the controller 340 may close thedomestic water valve 30 to flush the reverse osmosis filter 310 for asecond set time.

The second set time is not particularly limited, and may be any time aslong as it is sufficient to flush the reverse osmosis filter 310.

Meanwhile, the flushing tank 331 of the flushing portion 330 may alwayshave an air layer, as illustrated in FIGS. 14 to 16 .

For this purpose, the flushing tank 331 may be provided with a secondcheck valve 337 as illustrated in FIG. 13 . As illustrated in FIG. 15 ,when the water filtered by the reverse osmosis filter 310 is stored inthe flushing tank 331, the air inside the flushing tank 331 may not bedischarged externally.

As illustrated in FIG. 14 , when filtered water is not introduced intoand not stored in the flushing tank 331, since the flushing tank 331 isempty, an air layer exists in the flushing tank 331. That is, in thiscase, the flushing tank 331 may be entirely filled with air.

Further, as illustrated in FIG. 15 , when the filtered water is storedin the flushing tank 331, air in the flushing tank 331 may not bedischarged externally by the second check valve 337, and may becompressed inside the flushing tank 331.

Thus, in this case, the air layer may be also present in the flushingtank 331.

When the water filtered by the reverse osmosis filter 310 is stored inthe flushing tank 331, until the air layer of the flushing tank 331 isno longer compressed or until the air layer is compressed to apredetermined pressure, the filtered water stored in the flushing tank331 may be discharged from the flushing tank 331 by the pressure of theair layer.

The filtered water stored in the flushing tank 331 may be introducedinto the reverse osmosis filter 310 through the flushing purified watersupplying flow path 5 and the raw water flow path 1, and may flush thereverse osmosis filter 310, as described above.

Hereinafter, a water purifier according to a fourth embodiment of thepresent disclosure will be described with reference to FIGS. 17 to 20 .

FIG. 17 is a schematic view illustrating a water purifier according to afourth embodiment of the present disclosure, and FIGS. 18 to 20 areviews illustrating operations of a water purifier according to a fourthembodiment of the present disclosure.

There is a difference that water purifier according to the fourthembodiment of the present disclosure may include the water purifier 200according to the second embodiment of the present disclosure describedwith reference to FIGS. 9 to 12 , and may further include a connectionrelationship of the flushing purified water supplying flow path 5 in theflushing portion 430, and a flushing tank 431 in a flushing portion 430.

Therefore, the configurational difference will be mainly describedbelow, and the remaining configurations may be replaced with thosedescribed with reference to FIGS. 9 to 12 above.

In a water purifier 400 according to the fourth embodiment of thepresent disclosure, a flushing purified water supplying flow path 5 of aflushing portion 430 may be connected to a domestic water flow path 3connected to a non-filtration side portion 415 of a reverse osmosisfilter 410, and a purified water flow path 2 connected to a filtrationside portion 416 of a reverse osmosis filter 410, respectively, asillustrated in FIG. 17 .

In addition, a first check valve 435 or a flushing valve may be providedin the flushing purified water supplying flow path 5 to allow water toflow only in a direction of a domestic water flow path 3.

A flushing flow path 4 having a flushing valve 40 may be connected to araw water flow path 1.

In addition, a domestic water valve 30 may be provided in the domesticwater flow path 3.

The flushing portion 430 may include a flushing tank 431 connected tothe flushing purified water supplying flow path 5.

In addition, a second check valve 437 may be provided to prevent airfrom being discharged externally such that the air layer is alwayspresent in the flushing tank 431, during storage of the filtered water.

In such a configuration, when the water inflow valve 50 and the wateroutflow valve 10 are opened by the controller 440, water of watersource, for example, raw water may be introduced into the pre-treatmentfilter 410′ through a water inflow line, and may be firstly filtered, asillustrated in FIG. 18 .

The water filtered by the pre-treatment filter 410′ may be introducedinto the reverse osmosis filter 410 through the raw water flow path 1.

Further, as illustrated in FIG. 18 , the water filtered by the reverseosmosis filter 410 may be introduced into the post-treatment filter 410″through the purified water flow path 2 and may be filtered. The waterthat is not filtered by the reverse osmosis filter 410, i.e., thedomestic water, may be drained externally through the domestic waterflow path 3.

The water filtered by the post-treatment filter 410″ may flow in thewater outflow line, may be discharged externally through the dischargeunit 450, and may be supplied to a user.

After the water filtered by the filter units 410, 410′, and 410″, i.e.,the purified water, is discharged through the discharge unit 450 in apredetermined amount desired by a user, the controller 440 may firstlyclose the water outflow valve 10, as illustrated in FIG. 19 .

Thus, the water that is filtered by the reverse osmosis filter 410 andflows in the purified water flow path 2, i.e., the purified water may benot introduced into the post-treatment filter 410″, and may beintroduced into the flushing purified water supplying flow path 5 of theflushing portion 430.

Further, the water filtered by the reverse osmosis filter 410introducing into the flushing purified water supplying flow path 5 mayflow in the flushing purified water supplying flow path 5, and may bestored in the flushing tank 431.

After the water outflow valve 10 is closed and a predetermined first settime proceeds, the controller 440 may close the water inflow valve 50,and may open the flushing valve 40 of the flushing flow path 4.

Thus, the water filtered by the reverse osmosis filter 410 stored in theflushing tank 431 of the flushing portion 430 may be introduced into thereverse osmosis filter 410, i.e., the non-filtration side portion 415 ofthe reverse osmosis filter 410 through the flushing purified watersupplying flow path 5 and the domestic water flow path 3, as illustratedin FIG. 20 .

In this case, the first set time described above may be, for example, atime at which a sufficient amount of filtered water capable of flushingthe reverse osmosis filter 410 may be introduced into and stored in theflushing tank 431 of the flushing portion 430.

The first set time is not particularly limited, and may be any time aslong as it is necessary to flush the reverse osmosis filter 410.

The water introduced into the non-filtration side portion 415 of thereverse osmosis filter 410 may flush the non-filtration side portion 415of the reverse osmosis filter 410, and may be then drained externally asflushed water through the raw water flow path 1 and the flushing flowpath 4, as illustrated in FIG. 20 .

Further, after the water inflow valve 50 is closed, the flushing valve40 is opened, and a predetermined second set time proceeds, for example,the controller 440 may close the flushing valve 40 to flush the reverseosmosis filter 410 for a second set time.

The second set time is not particularly limited, and may be any time aslong as it is sufficient to flush the reverse osmosis filter 410.

The control method of the water purifier described above with referenceto FIGS. 7 and 8 may also be applied to the water purifiers according tothe second to fourth embodiments described above with reference to FIGS.9 to 20 . Although not illustrated in FIGS. 9 to 20 , a flow rate sensormay be provided in the purified water flow path 2 of the water purifiersaccording to the second to fourth embodiments, and a discharge of adomestic water may be shut-off, or the shut-off of the discharge may bereleased, depending on the result of comparing an accumulated flow rateat the time of one-time extraction of the purified water calculated onthe basis of a flow rate of the purified water measured by the flow ratesensor, and a predetermined flow rate value. While exemplary embodimentshave been shown and described above, it will be apparent to thoseskilled in the art that modifications and variations could be madewithout departing from the scope of the present disclosure as defined bythe appended claims.

What is claimed:
 1. A water purifier comprising: a filter unit filteringwater supplied from a water source and including a reverse osmosisfilter divided into a non-filtration side portion and a filtration sideportion by a reverse osmosis membrane; a discharge unit discharging thewater filtered by the filter unit to an outside of the water purifier; aflushing portion connected between the non-filtration side portion andthe filtration side portion; and a controller configured to flow thewater filtered by the reverse osmosis filter to the non-filtration sideportion through the flushing portion so as to flush the reverse osmosisfilter, wherein the non-filtration side portion is connected to a rawwater flow path flowing the water into the reverse osmosis filter, andto a domestic water flow path draining non-filtered domestic water thatdoes not pass through the reverse osmosis membrane, wherein thefiltration side portion is connected to a purified water floe pathdischarging filtered water that passes through the reverse osmosismembrane, and wherein the flushing portion includes a flushing purifiedwater supplying flow path connected to the raw water flow path and thepurified water flow path, respectively, or connected to the domesticwater flow path and the purified water flow path, respectively.
 2. Thewater purifier according to claim 1, wherein the controller iselectrically connected to a water inflow valve for supplying the waterto the filter unit, and to a water outflow valve for discharging thewater filtered by the filter through the discharge unit, and wherein thecontroller opens and closes the water inflow valve and the water outflowvalve with a predetermined time difference to flow the water filtered bythe reverse osmosis filter to the flushing portion.
 3. The waterpurifier according to claim 1, wherein the filtration side portion isconnected to the purified water flow path discharging the filtered waterthat passes through the reverse osmosis membrane.
 4. The water purifieraccording to claim 3, wherein the flushing purified water supplying flowpath comprises a check valve or a valve flowing the water only in adirection of the raw water flow path.
 5. The water purifier according toclaim 3, wherein the flushing purified water supplying flow pathcomprises a check valve or a valve flowing the water only in a directionof the domestic water flow path.
 6. The water purifier according toclaim 5, wherein the raw water flow path is connected to a flushing flowpath having a flushing valve.
 7. The water purifier according to claim3, wherein the flushing portion further comprises a flushing tankconnected to the flushing purified water supplying flow path and storingand discharging the filtered water.
 8. The water purifier according toclaim 7, wherein an air layer is always present in the flushing tank. 9.The water purifier according to claim 3, wherein the purified water flowpath further comprises a flow rate sensor measuring a flow rate ofpurified water flowing per unit time, and the controller controls adomestic water valve disposed in the domestic water flow path to shutoff the draining of the non-filtered domestic water, when an accumulatedflow rate calculated on a basis of the flow rate of the purified waterflowing per unit time while the purified water is extracted once islower than a predetermined amount, and controls the domestic water valveto release the shut off of the non-filtered domestic water, when theaccumulated flow rate is equal to or larger than the predeterminedamount.